The use of high strength polymers to construct structural components of a handgun, such as the grip frame, have been known for some time. In some examples, such as various models of the popular GLOCK® handgun, certain parts made of metal are embedded in a polymer frame as it is injection molded. In other examples, a polymer grip frame is used with removably attachable metal components, or has metal frame parts that are separable from a polymer grip frame or grip component.
While the use of polymer materials for structural parts in a handgun are very effective at reducing its weight, the polymer materials flex or fatigue at rates different from the metal components that are inserted or embedded in the polymer. As a result, particularly over extended time and use, critical spacing dimensions, such as between pivot points of parts in the action that work together, may change, increasing the possibility of a failure.
Flat surfaces that slide over each other in a mechanical assembly, such as a firearm, may fit very closely. Oil-type lubricants can be effective on these sliding surfaces for a limited time, or until metal filings or other particulate debris accumulates in the tight clearance. Captured in place, these particles can caused increased wear, galling, and even seizing of the parts.